The present invention generally relates to electrical insulators, and more particularly relates to an electrical insulator (also referred to herein as an “isolator”) for electrically isolating different electrical ground systems by locating the isolator between and interconnecting separated lengths of electrically conductive refrigerant lines which extend between the ground systems and carry a liquid refrigerant therethrough for cooling electronic devices.
Electronic equipment is known to generate heat which must be rejected from the device to prevent overheating and malfunction. Some industries require concurrent operation of many electronic devices positioned in close proximity to each other which generates an enormous quantity of heat which must be constantly drawn away from the electronic devices. The electronic devices (e.g. computer servers) are typically placed in electronic device frames or racks which are placed in repeating rows within a large room called a “data room” or “data center”. Various methods are used to cool the electronic devices. For example, it is known to use a liquid refrigerant such as R134a which is pumped through metal lines to a heat exchanger located in close proximity to the electronic device. Metal lines are preferred since they prevent permeation of the refrigerant through the walls of the lines. One potential drawback of using electrically conductive metal lines to carry the refrigerant from the pump to a location close to the electronic devices is interference between the ground of the A/C powered refrigerant pump and the ground of the D/C powered electronic devices. While one potential solution would be to use nonconductive lines such as PTFE or ETFE, for example, such nonconductive lines is susceptible to refrigerant permeation due to the molecular make-up of these non-conductive materials. For short lengths of lines, this is not usually a problem, but in applications where long lengths of lines are required (e.g., as in the above-described data rooms), the surface area of lines is necessarily higher and the potential for refrigerant leakage therethrough is much greater.
As stated above, while metal lines are preferred for carrying the refrigerant from the pump to the heat exchangers located in proximity to the electronic devices, since the metal lines are electrically conductive, the potential exists that the different electric grounding schemes of the A/C powered pump and D/C powered electronic devices may interfere with one another through these interconnecting, conductive metal lines. Furthermore, the refrigerant itself is generally non-conductive and may develop a static electric charge as it flows through a non-conductive material such as the above plastics due to the triboelectric effect. A need therefore exists for an isolator that will electrically isolate the A/C and D/C grounding schemes without any refrigerant leak therethrough and without causing any arcing of static electric charge from the refrigerant through the isolator component.